Resetting-to-zero mechanisms for seconds, minute, and hour hands

ABSTRACT

In a timepiece wherein the second, minute and hour hands are rotated about a common axis, an externally operated hand position resetting arrangement is provided for shifting a second hand connection lever and a minute and hour hand correction lever into engagement with respective cams to accomplish the resetting of the hands to a zero position.

United States Patent Komiyama et al.

[ 1 June 6, 1972 RESETTING-TO-ZERO MECHANISMS FOR SECONDS, MINUTE, ANDHOUR HANDS Inventors: Katsuhiko Komiyama; Yoshio Iinuma,

both of Tokyo, Japan Assignee: Citizen Watch Company Limited, Tokyo,

Japan Filed: Apr. 19, 1971 Appl. No.: 134,944

Foreign Application Priority Data Apr. 20, 1970 Japan ..45 32975 June 4,1970 Japan... WAS/55024 June 5, 1970 Japan ..45/55602 U.S. CL. ..58/74Int. Cl. t r .....G04f 7/04 Field of Search ..58/74-78, 85.5

[56] References Cited UNITED STATES PATENTS 455,026 6/1891Sandoz-Barbier ..58/76 843,887 2/1907 Gerson 58/74 2,679,135 5/l954Hanhart ..58/76 Primary ExaminerRichard B. Wilkinson AssistantExaminer-George H. Miller, Jr. A!t0rneySughrue, Rothwell, Mion, Zinn &Macpeak [57] ABSTRACT In a timepiece wherein the second, minute and hourhands are rotated about a common axis, an externally operated handposition resetting arrangement is provided for shifting a second handconnection lever and a minute and hour hand correction lever intoengagement with respective cams to accomplish the resetting of the handsto a zero position.

5 Claims, 23 Drawing Figures ,PATENTEDJUH we 3,667,212

SHEET 2 [IF 8 PATENTEUJUH s 1972 3, 567. 212

SHEET 5 or 8 F|G.9A

FIGQB RESETT'ING-TO-ZERO MECHANISMS FOR SECONDS, MINUTE, AND HOUR HANDSThis invention relates to a unique hands correcting or resettingmechanism for timepieces wherein by manipulating a certain operatablemember to which access from outside is assured, the seconds hand of thetimepiece is reset to zero and, at the same time, the minute hand isalso returned to its regular position when it is positioned within acertain predetermined region, for example, about 12 or oclock of thetimeindicating dial of the timepiece.

The conventional timepiece generally represents such a design that inorder to set the time indication of the timepiece to anhourly'time-casting signal, as an example, the hour and minute handsmust be operated regardless of the position of the seconds hand, thusoccasional advancement or retardation of the latter being ignored andtherefore a small time indication error occurn'ng almost each time forevery time setting job. 1 K

For overcoming such conventional drawback, it is known to provide thetimepiece with a stopper mechanism for the seconds hand. In this kind oftimepieces, when it is desired to set the hands to an hour signal, theseconds hand is brought provisionally into stop by manipulating thestopper mechanism and mustbe started at the exact moment where thetime-indication of the timepiece is in coincident registration with theexact time point. In addition, the seconds hand setting should becarried into effect in such a way that, generally speaking, the secondshand must be stopped at the position of 12 oclock. Therefore, it may besaid that this kind setting of seconds hand is highly inconvenient andthus has much to be desired. I

On the other hand, the conventional stop watch is provided with aresetting-to-zero mechanism by which it is possible to return itstime-indicating hands to zero when desired. Such mechanism is alsofitted in certain type of tachometer. But, it

should be noted that in the stop watch, it does not provide suchpossibility for returning the regular time-indicating hands to zero. Onthe other hand, the tachometer mechanism is substan tially differentfrom the purpose and nature of the regular timepiece.

It is the main object of the invention to provide a unique handsposition correcting or resetting mechanism for regular timepieces,substantially obviating the aforementioned conventional drawbacks.

These and further objects, features and advantages of the invention willbecome more apparentwhen read the following detailed description of theinvention by reference to the accompanying drawings illustrative ofseveral preferred embodiments of the invention.

In the drawings:

FIG. 1 is a schematic plan view of essential parts of a first embodimentof the invention, wherein, however, the timekeeping gear train and itsrelated various mechanisms of a timepiece have been omitted from thedrawing for the demonstration of the main principle of the invention.

FIG. 2 is an enlarged sectional elevation of main working parts of aconventional timepiece movement fitted with the hands correctingmechanism shown in FIG. 1.

FIGS. 3A and 3B are a part of the timepiece movement 'shown in FIG. 2and in two different operational positions of said mechanism,respectively.

FIGS. 4A and 4B are schematic plan views, respectively, of a secondembodiment of the invention and in two different operational positionsof said mechanism.

FIG. 8 is an enlarged plan view of a fifth embodiment of the invention.

FIGS. 9A and 98 represent in combination a sectional elevationsubstantially taken along a broken section line P-Q shown in FIG. 8, theseparation lines X-X showing that FIGS. 9A and 98 can be joined togetherby overlapping these section lines each other.

FIGS. 9C and 9D represent in combination a single sectional elevationtaken substantially along a broken section line R-S shown in FIG. 8, theseparation lines Y-Y showing that FIGS. 9C and 9D can be joined togetherby overlapping them into a single line; and

FIGS. 10A-10C are schematic plan views of a sixth embodimentof theinvention shown in three different operational positions thereof.

Referring now to FIGS. 1, 2, 3A and 3B, the first embodiment of theinvention will be described in detail hereinbelow:

Numeral 1 represents part of a conventional plate of a timepiecemovement and 2 is a mounting plate for the gear train to be described,said mounting plate being arranged in parallel to the plate 1 andrigidly fixed thereto, although the fixing means have been omitted fromthe drawing only for simplicity. A stationary support member 3 is alsofixedly attached to both plates 1 and 2, although the fixing means havebeen omitted from the drawing again for simplicity. 4 represents anintermediate mounting plate shown only partially and attached rigidly tothe plates 1 and 2, although the fixing means have been omitted from thedrawing.

5 represents a seconds hand arbor; 6 a seconds hands pinion; 7 a secondgear; 8 a cannon pinion; 9 a cannon wheel; 10 a minute wheel; and 11 athird gear. These members 5-11 are arranged and mounted asconventionally relative to said parts 14 as is commonly known amongtimepiece engineers.

Numeral 12 represents a cam provided for setting-to-zero of secondshand, not shown, said cam being formed into a heart Configuration whenseen in FIG. 1 and fixed to arbor 5. A wire spring 13 is composed of a Ushaped part and two parts standing up from the end of it as shown inFIG. 2. The U-shaped part of the wire spring 13 frictionally embracesaring recess 6a formed on the seconds hand pinion, and the two standingparts pass through a slot 12a formed through the cam 12. By this springbias arrangement, the cam 12 frictionally combines with the seconds handpinion and is entrained with regular time keeping rotation of thelatter.

A second cam 14 is formed with three separate vee-shaped notches 14aarranged radially at equal angular intervals and rigidly andconcentrically to the minute wheel 10.

A lever 15 adapted for regulation of the position of cam 12 is pivotablymounted at its root end on the support member 3 by a studded pivot pin16. At the free end of the lever 15, there is formed with a flat surface15a, said lever being formed further with a recess 15b (FIG. 1) at anintermediate point between the both extremities thereof.

A ring piece 17, most clearly seen in its axial section in FIG. 2,having an inwardly and convexedly curved sectional configuration as at17a, is rotatably mounted on a cam-position regulator pin 18 and kept inslidable contact with the lower surface of support member 3 and with theupper surface of the plate 1. The pin 18 passes through an elongatedslot 3a formed through the member 3, the inwardly convexed bore 17aformed in ring member 17 and a further elongated slot 10 formed throughthe plate 1, representing the lower end 18c emerging downwardly from thelast-mentioned slot la. As may be clearly seen from the drawing,regulator pin 18 can slide along and tilt in a vertical plane includingthe center of minute wheel 10. The pin 18 is formed with an enlargedpart 18a which is positioned in proximity to the upper end 18b of thepin, thereby an excess axial movement thereof being positively limitedwithin a predetermined small distance, said upper pin end 18b being keptin slidable engagement with said recess 15b, while the lower end of saidpin is adapted for contact with the second cam 14.

There is provided a spring member 19, the root end of which is pivotablymounted on the member 1 by a pivot pin 23 in such a way that the ringmember 17 is resiliently urged to move remotely from arbor 5.

An operating member 20 which is shaped into a slide or push buttonslidably mounted on the plate 1, although the mounting means have beenomitted from the drawing only for simplicity. The inner end 20a of thepush button 20 is brought into contact with the outer peripheral surfaceof the axially perforated ring piece 17. The push button may preferablybe the conventional winding stem of the time piece. When the push buttonis pushed in, the ring piece 17 will be moved towards the seconds handarbor 5 against the action of the urging spring 19. The conventionalbarrel spring is shown only partially by an imaginary line at 21.

The operation of the first embodiment so far shown and described is asfollows:

When the push button 20 is pushed in, in the direction of an arrow A,"it will drive the ring piece 17 towards the seconds hand arbor 5 whenthe second cam 14 occupies the position shown in FIG. 1 or a neighboringone thereto and regardless of occasional position of the first cam 12,thereby the regulator pin 18 being urged to shift in the same direction.Since, in this case, the upper end 18b of pin 18 is kept in engagementwith recess 1512 on lever 15, the latter is rotated in clockwisedirection in FIG. 1, while, at the same time, the lower end 18c of saidpin 18 will enter into one of the vee-shaped notches 1.40 on second cam14. It should be noted that except under such operational conditionsthat the conventional minute hand, not shown, and thus the second cam 14do not occupy their position for representing the correct time, thelower pin end 180 is brought into contact with either wall surfacedefining a notch 14a. The related parts of minute wheel and camposition-regulating lever are so designed and arranged that the torquefor turning the cannon pinion 8 by minute wheel 10 is substantiallylarger on account of its specific gear ratio than that necessary forrotating the lever 15 by the upper pin end 18b, the pin end 18c, uponcontact with the notch wall 14a, will provisionally stop its advancingmovement, while the upper pin end 18b will act upon the lever 15 torotate it to a substantial degree so that the flat wall surface 15a oflever 15 will be brought into pressure contact with first cam 12 whichis rotated in turn to a certain required degree. In this way, the spring13 fixedly attached to cam 12 and frictionally embracing the ring recess6a of seconds hand pinion 6 will be brought into slippage from pressurecontact therewith so that the cam 12, regardless of its occasionalposition, is brought into its engaging position as shown in FIG. 1,thereby at first the seconds hand, not shown, being returned to itszero-position at 12 oclock indication point on the time-indicating dial,again not shown, and next, with the upper pin end 18b, having stopped atthis stage for holding the seconds hand at its zero position, the pin 18will be tilted in counter clockwise direction in FIG. 2 with the lowerpin end 18c forcibly pushed into the related notch 144, so as toregulate the position of second cam 14 into such that the minute hand isreturned to its regular position such as the zero position. At the sametime, minute wheel 10' will act upon cannon wheel 9 which will influenceupon the hour hand, not shown, so as to occupy the correct time.

As will be easily understood from the foregoing and by consulting withFIG. 3A, the operational range for setting of the minute hand to itscorrect position when it is near the correct time in either a plus orminus direction relative to the regular time-keeping position, may bedefined by properly selecting the dimension of the vee-notches 14a,especially the outwardly diverging angle thereof. When considering,however, the purpose and object of setting the minute hand to itscorrect position, a certain, relatively small range of time indication,on opposite sides of its regular position, will do for the desiredpurpose.

It will be further observed from the foregoing that by pushing thebutton 20 to a lighter degree, the seconds hand only can be reset tozero.

Now, it is assumed that the second cam 14 occupies a certain differentposition than that shown in FIG. 1 at the time of push-in of theoperating button member 20, wherein the lower end 180 of pin 18 is keptin contact with the peripheral surface of cam 14 so that it can notenter into any one of the notches 14a. Under these conditions, a pushupon the pin 18 will swivel the latter in the plane including thedrawing paper and in clockwise direction about the lower end oi" saidpin, as shown in FIG. 3B so that the upper pin end 18b only iseffectively moved to shift the lever 15 for resetting the seconds handto zero. i

Upon release of the finger pressure from push button 20, a certainbiasing member such as a spring, not shown, will act upon and the button20 will be returned to its original position. Thus, lever 15 and ringpiece 17 will be returned to their respective starting position underthe action of spring 19.

Next, referring to FIGS. 4A and 4B, the second embodiment will now beillustrated. v i

In these figures, numeral 101 represents a stationary timepiece membersuch as conventional plate or the like; 102 a first cam similar to thatshown at 12 in the foregoing and attached to seconds hand arbor 103; 104a second cam similar 7 to that shown at 14 in the foregoing and fixedlyattached to the minute wheel, not shown; 105 an intermediate lever whichis pivotably mounted at an intermediate point between its both ends by apivot 106 on the base plate 101 and having a pin 107 at its one end anda further pin 108 positioned between the said one end and the pivot 106;109 a member similar to that shown at 20 in the foregoing and having itsinner end 109a adapted to establish a pressure contact with pin 108 whenit is pushed towards the seconds hand arbor, so as to rotate the lever105 in counter clockwise direction; and 1 10 a first campositionregulating lever which is pivotably mounted by a pivot 111 on the baseplate 101, having at its one end straight end edge 1 10a and twoseparate arms 11% and 1 10:; at its opposite end and defining a recess110d formed thereby and therebetween, thus representing a twin fingeredfork portion. The recess 110d thus formed is always kept in engagementwith the one end a of the intermediate member 105 and one of the forkfingers l10b is formed with a curved surface 1l0b having a radius equalto the distance as measured between the pivot point of said lever 105and the tip end 105a thereof. This lever is adapted for resetting theseconds hand to its zero position, as will become apparent as thedescription proceeds. v

Numeral 112 represents a second cam-position regulating lever forcorrecting of the minute hand, said lever 112 being pivotably mountedwith its one end on base plate 101 by means of a pivot 113 and with itsopposite end 112a adapted for engagement with one of vee-notches 104aformed on second cam for correcting the hour and minute hands as before,when this lever is rotated in counter clockwise direction; 114 a springone end of which is fixedly attached to said base plate 101, theopposite end 114b of said spring being kept always into engagement withsaid lever 112 which is thus urged to rotate in clockwise direction. Inthe latter case, motion will be transmitted from lever 112 through pin107 engaging therewith, to said intermediate or motion transmissionlever 105 so as to rotate the latter in clockwise direction. Motion willbe thence transmitted further to lever 110, so as to rotate it incounter clockwise direction. Numeral 115 represents a stop memberadapted for limiting the range of counter clockwise rotation of thelever l 10.

The operation of the second embodiment is as follows:

When the operating member 109 to which access is made easily fromoutside as before, is pushed in as shown by an arrow A, the inner end109a thereof will be brought into pressure contact with pin 108 andmotion will be transmitted therefrom to motion transmission lever 105which is thus caused to swivel around its pivot 106 in counter clockwisedirection. In this way, the end 110a of lever 110 is brought to itscertain predetermined position for performing said resetting. On theother hand, lever end 105a is released from engagement with recess 110dand then brought into contact with the curved portion 11% of theforkfinger 110b. At this operational stage, lever 112 is acted upon byspring 114 and thus moved to rotate so much by the pin 107 on lever 105.At this time, the end 112a of lever 112 has not yet brought intoengagement with cam 104 (refer to FIG. 48). I

When the cam 104 occupies within a certain operational rangecorresponding to a certain time-indicating range of the minute handaround the correct time indication and under these conditions, a fingereffort is applied to the manually operatable member 109 being furtherpushed in, lever end 105a will be caused to slide along the curvedsurface 110b on fork finger lb and the pin 107 will act upon lever 112against the action of spring 1 14, thus this lever being caused torotate in counter clockwise direction. In this way, the end 112a oflever 112 will invade into the recess 104a on second cam 104 and broughtinto pressure engagement therewith, so as to regulate the position ofsaid cam adapted for performing the required correcting operation forthe minute hand, not shown. In this way and as in the same way asbefore, the hour hand, not shown, is brought into its correcttime-indicating position.

By releasing the operators finger pressure from the operating member109, spring force at 114 will become effective to return first andsecond cam-regulating levers 1 10; 112, motion transmission lever 105and operating member 109 to their respective starting position (refer toFIG. 4A).

Should the minute hand be positioned outside of the predeterminedcorrecting range, the operating member 109 is further pushed in to itssecond operational position upon completion of the zero-resetting of theseconds hand, thereby the lever end 112a being brought into engagementwith cam 104 at its plain peripheral surface other than the .vee-notches104a and thus no correcting operation of minute hand is initiated in anyway.

' In the foregoing first and second embodiments, the second cam has beenshown as rigidly attached to the minute wheel, as arepresentative.embodiment. It will be seen, however, the invention isnot be limited thereto. In practice, however, the cam can be fixedlyattached to any selected one of related gears with minute wheel Forinstance, it can be attached with setting wheel, cannon pinion or thelike member constituting the minute-indicating gear train 'part system.In this case, the vee-notches must be modified correspondingly in itsnumber, size and the like design data. I

Next, referring to FIGS. 5A,"5B, 5C, 5D and 6, the third embodiment ofthe invention will be described in detail.

In this arrangement shown, the timepiece may either be of the electronicor mechanical one. In the former case, it is assumed that power is fedfrom a balance wheel to the gear train. In the latter case, power may betransmitted through the third or the line wheel to the gear train.

In this embodiment, numeral 230 represents the conventional plate; 222 amounting plate for the gear train; 223 an intermediate mounting plate;225 a seconds hand pinion mounted on seconds hand arbor 244; 216 a thirdwheel; 217 a fourth wheel; and 218 a second wheel which rotates inunison with second wheel shaft 219 in the regular time-indicatingoperation, yet there being a relative slip therebetween duringresetting-to-zero of the minute hand, not shown. As inthe foregoingembodiments, the both members 218 and 219 are frictionally coupledtogether and rotatable in unison with each other for a turning torquebelow a certain predetermined value.

Numeral 240 represents a cannon pinion; 221 a cannon wheel, 222 a minutewheel; 233 a first cam having a heart cam configuration as before andadapted for resetting-to-zero of the seconds hand, not shown; 244 theseconds hand arbor as above referred to. Numeral 224 is an urging springattached to said cam as before; 226 a wheel adapted for carrying out theresettingfto-zero of theminute hand, not shown and attached fixedly witha second cam 215 having vee-notches 215a as before on its outerperiphery and adapted for perfonning the resetting-to-zero, and furtherwith a gear 227 adapted for the same purpose. Numeral 228 represents asecond gear wheel fixedly attached to second wheel shaft 219 and keptalways in meshing with said gear 227 so as to perform the minute handresetting.

A lever 201 adapted for perfomiing the minute hand resetting, ispivotably mounted with its one end 201a on a base plate such asconventional plate or mounting plate as before, by means of a pivot pin202 studded thereon. This lever 201 is formed with a bent-down straightedge part 201b, a rounded projection 201C adapted for cooperation withcam 215, an arc-shaped part 201d having a radius extending from thepivot point of said lever; a straight edge part 201s neighboring to saidpart 201d, a rear curved part 201f and an arm part 201g. Numeral 203represents an operating member which has an easy access from outside andis adapted for cooperation with said part 2011). A lever 204 is used forperforming the resetting-to-zero for the seconds hand, not shown andpivotably mounted on the base plate 230 by means of a pivot 205 studdedthereon, said lever being provided with an inclined straight part 104a,and further with a pin 206 and a bentup straight edge part 204k adaptedfor cooperation with arc-shaped part 201d and a rear curved part 201i.The lever 204 is further provided with a straight edge part 204c on itsopposite end for cooperation with cam 233. An urging spring 207 isprovided the root end 207a of which is fixedly attached to the baseplate 230 by meansof a fixing pin 209 and a set screw 208 as shown,while the free end 2071: of the spring is always kept in engagement withthe projecting arm 201g of lever 201, thereby the latter receiving aresilienturging force for turning the lever in counter clockwisedirection. At the same time, a resilient urging force is transmittedtherefrom through the bent-up part 204b of said lever 004 kept normallyin engagement with rear curved part 201 f of lever 201 to that 204, thelatter being urged to rotate in counter clockwise direction. On the baseplate 230, there is fixedly mounted a stationary stop pin 210 adaptedfor limiting the counter clockwise rotational range of said lever 204.

The operation of the third embodiment is as follows:

When the operating member 203 is pushed in as before and as hinted by anarrow A", the inner end 203a thereof is brought into pressure contactwith the bent-down straight edge part 20lb of lever 201, the latterbeing swivelled thereby about its pivot 202 in clockwise direction andthe straight edged end part 2012 of said lever 201 being brought intopressure engagement with pin 206 on the lever 204, so as to rotate thelatter lever in clockwise direction. In this way, the straight edge part2040 of lever 204 isbrought into cooperating engagement with'cam 233,thereby the latter being regulated to occupy a certain predeterminedposition adapted for making a resetting-to-zero of seconds hand, notshown. Until this time, the pin 206 on lever 204 has been brought intopressure and cooperative engagement with arc-shaped part 201d having aradius of curvature, equal to the distance extending from pivot point202, upon slippage from contact with said part 2012, while the lever 201adapted for resetting-to-zero of the minute hand, not shown, has not yetbeen attained such position that the rounded projection 2010 is broughtinto engagement with cam 215 (refer to FIG. 5B). 1

When it is assumed that the cam occupies such position that the minutehand is positioned within a predetermined range of time indication aboutthe correct time position as its center, and the operating member 203 isfurther pushed in, the lever 201 is caused to rotate in clockwisedirection, butthe lever 204 is kept stationary at the present positionby virtue of the engagement of said pin 206 with said arc-shaped part201d having its center positioned at the pivotal point of said lever201. At the same time, the projection 201a of lever 201 will invade intothe vee-notch2l5a and brought into cooperative engagement therewith,thus the cam 215 being checked to remain its position adapted forperfomting the setting-to-zer'o of minute hand. Therefore, motion istransmitted to second gear wheel 228 for the zero-resetting and theminute hand is brought to its zero position. Motion is transmitted fromminute wheel 222 to cannon wheel 221 so as to rotate the latter forindicating the correct time (refer to FIG. C). At this time, secondwheel 218 kept in mesh with the third wheel will make a frictionalslippage relative to the center wheel (second wheel) arbor operativelyconnected through cannon pinion 240 with the minute hand asconventionally.

At a time-setting operation, minute wheel 222 is rotated so as tothereby rotate cannon pinion 240 and cannon wheel 221 for correspondingrotation of the minute and hour hands. During this time-settingoperation, arbor 219 and pinion 240 are caused to rotate in unison andmotion is transmitted through center wheel 228 mounted on the arbor 219and provided for zero-resetting of the minute hand to the wheel 226,thereby the latter being brought into rotation. In this way, otherwisepossible unintentional transfer of the related parts from the positiondestined for the resetting of minute hand to its zero position andcaused by the regular time-setting operation can efiectively prevented.At this time, a slippage will occur between the arbor 219 and the gear218, as in the case of the zero-resetting of minute hand.

Upon release of the operators finger pressure acting upon the operatingmember 203, spring force at 207 becomes effective so as to return thelever 201 for minute hand to its original position. At the same time,the lever 201 will act by its rear curved part lf upon the lever 204 forseconds hand at the bent-up part 204b, thus the latter lever being alsoreturned to its original position (refer to FlG. 5A).

When the minute hand should be positioned outside the predeterminedresettable-to-zero range; a further manual push-in pressure must beimposed upon the operating member 203 for shifting it to a secondoperating position upon returning of the seconds hand to its zeroposition. In this way, lever 201 is brought by its rounded projection201:: into pressure contact with cam 215 at its outer plain peripheryother than vee-notch 215a and therefore, the minute hand can not returnto its zero position (refer to FIG. 5D).

Next,'referring to FIGS. 7A, 7B, 7C and 7D, the fourth embodiment of theinvention will be described in detail. As will become clear from thedescription to be set forth, the foregoing levers for resetting-macro ofseconds hand and minute hand, respectively, have been united into onemember in the present embodiment. I

In these figures, the unified sole resetting-to-zero lever is shown at301, one end 301a of which is pivotably mounted on a stationary basemember of a timepiece movement, such as conventional plate 300 thereof,by means of a pivot pin 302 studded thereon. This lever 301 is formedwith a projection 301b adapted for cooperation with cam 315 forresetting the minute hand, not shown, to its zero position; a stopperportion 3011) having an arc-shaped edge with a radius of curvature equalto the distance from the pivot 302 as its center and adapted forengaging contact with cam 313 for zero-resetting of the seconds hand,not shown, and for keeping the cam in its stationary position regardlessof rotational movement of the lever 301; a curved actuating portion 301dadapted for initiating the zero-resetting of seconds hand; and amotion-receiving edge part 301e adapted for cooperation with the innerend 303a of a manipulating member 303 such as conventional winding stem.The lever 301 is further provided with a pin 304 fixedly mounted thereonand kept in pressure contact with an elongated spring 307.

. This spring 307 has its root end 307a fixedly attached to.

base plate 300 by means of a pin 309 passing forcibly through thespring, and a set screw 308. As briefly mentioned hereinbefore, the freeend 307b of spring 307 is always kept in pressure contact with said pin304, so as to urge the lever 301 to rotate in counter clockwisedirection.

A stopper pin 310 is fixedly mounted on base plate 300 for limiting therange of counter clockwise rotation of the sole resetting lever 301.

The operation of the fourth embodiment so far shown and described isas'follows:

When the operator pushes the operating member 303 inwards as hinted byan arrow A', the inner end 303a thereof is brought into pressure contactwith the sole reset lever 301 at its motion-receiving portion 301a sothat the lever is rotated clockwise around its fixing screw 302. In thisway, the portion 301d of lever 301 is brought into engagement with cam313 which is regulated to its predetermined effective position adaptedfor perfomiing the seconds hand resetting. At this time, the cam 313 iskept in contact with the portion 301c of lever 301 and thus theprojection 301b thereof is not yet brought into engagement with cam 315for zero-setting of the minute hand (refer to FIG. 7B).

When the cam 315 occupies a position corresponding to the minute handkept within its predetermined zero-resettable range, a further push-inoperation of the member 303 will invite a further clockwise turningmovement of the reset lever 301, thereby the actuating projection 30]!)invading into the vee-notch 315a on cam 315 which is thus checkedagainst unintentional motion and held at its operative position. At thisstage, the seconds hand resetting cam 313 is kept in engagement with thepart 3010 of lever 301 and thus the seconds hand, not shown, is held inits zero-reset position (refer to FIG. 7C).

Upon release of the operators finger pressure fromv the reset lever 301,the spring force at 307 becomes effective to return the latter to itsoriginal position (refer to FIG. 7A).

'When the minute hand, not shown, is situated outside the predeterminedresettable range and a further and slightly intensified finger pressureis applied to the operating member 303, the checking projection 3010 oflever 301 will naturally be brought into engagement with cam 315, yetwith its plain peripheral surface 315b other than the notch 315athereof. Therefore, the minute hand can not be reset to its zeroposition (refer to FIG. 7D).

It will be seen from the foregoing that the seconds hand reset lever andthe minute hand reset lever can be provided ether in a separated mode orin a common and unified mode, as occasion may desire. The occasionaladoption of an intermediate motion-transmitting member as referred tohereinbefore does not influence upon the nature of the presentinvention.

. Although not shown, an additional spring may be provided for theoperating inember which spring acts upon the latter when the minute handresetting means is not brought into the minute hand reset cam even uponexecution of the zero-reset of the seconds hand. In such modifiedarrangement, the minute hand reset operationwill be encountered with acorrespondingly stronger spring resistance than the case of the secondshand resetting operation. Therefore, the operator can discriminateeither manipulating operation only through his manual touch. Y i

In a further modification, again not shown, the cam configuration is somodified that the time setting may also be performed to any desired timeother than those corresponding to the regular hour signals.

Next, referring to FIGS. 8, 9A, 9B, 9C and 9D, the fifth embodiment willbe described hereinbelow in detail:

In FIG. 8, numeral 401 represents a rigid and stationary member such asconventional plate, balance wheel-mounting bridge or the like of anelectronic timepiece movement, preferably the plate. Numeral402represents a battery unit detachably mounted on the plate 401;Balance wheel is shown only by its outer configuration with an imaginarycircle at 403, said wheel being mounted as conventionally on balancewheel arbor 418. Seconds hand reset cam 417 is attached at the center415 of the timepiece onto a conventional seconds hand arbor 431, and inthe similar way, minute hand reset cam 416 is attached to a conventionalminute hand arbor 429 concentrically arranged to the former arbor 431.On the other hand, in proximity to the movement center 415 and to thebalance wheel arbor 418, there are provided conventional escapemechanism and timekeeping gear train, including index wheel 420; sixthwheel 421; fifth wheel 422; fourth wheel 426; second wheel 425; thirdwheel 423 and minute wheel 424. These members are, however, designed andarranged as con- .ventionally and therefore, a detailed analysis thereofhas been omitted only for simplicity.

The zero-reset mechanism according to this invention adapted for thereset of seconds hand and hour and minute hands is arranged at thediametrally opposite side relative to the conventional gear train andabout an imaginary line connecting the center 415 of the timepiecemovement with the axis of balance wheel arbor 418.

In these figures, a first cam 417 is arranged at the time-piece center415 for performing the zero-resetting of the seconds hand, not shown. Asubstantially L-shaped lever 411 adapted for controlling thezero-resetting of the seconds hand is pivotably around a pin 411fmounted on, an intermediate mounting plate 430 near the root end of anurging spring 409 which is mounted on base plate 401, preferably theconventional plate of the timepiece movement, by means of pins 410 and411f which are studded on plate 401. Although the lever 411 is separatednormally from said cam 417 as shown clearly in its full line position inFIG. 8, this lever is brought into cooperating contact with said camduring zero-resetting operation for the seconds hand, as shown bychain-dotted lines'in the same figure.

The longer arm 411b of lever 411 is formed at its free end with astraight edge portion 41 1a by which the lever is brought intocooperation with said cam 417, a projecting finger 411c and a shoulder411d being formed at the bend of said L- shaped lever 411, so as toprovide a curved recess 41le formed therebetween.

' A transmission lever 406 is pivotably mounted on the intermediateplate 430 by means of a pivot pin 405 studded on base plate 401. Theopposite end of lever 406 extends to such a position where the inner endof an operating member 404 formed into a push button or conventionalwinding stem, as the case may be. An extension 406a is further formed onsaid lever 406, the free end of said extension extending into saidrecess 4112. With the reset mechanism positioned in its ofi serviceposition, the free end of said extension 406a is kept in contact withsaid finger 411e, as demonstrated in FIG. 8 by full line.

Urging spring 409 is kept in pressure contact with a further lever 407for hour and miriute hands, not shown, said lever 407 being partiallyand rigidly connected from below with transmission lever 406 by means offixing pins 405 and 408 in such manner that a clockwise urging force istransmitted to the combination of transmission levers 406 and 407rigidly connected with each other, so as to rotate this combined leversabout the pin 405. These combined levers are kept in pressure contactwith the inner end of operating member 404.

Transmission lever 407 is formed with an elongated arm 407a extendingintegrally therefrom and substantially radially and inwardly, the freeend of this arm invading into a recess 414 formed on a hour and minutehands reset lever 413 which is pivotably mounted on the base plate 401by pivot pin 412. Spring 409 acts upon the lever 407 so that the freeend of arm 407a is kept normally in resilient pressure contact with oneside wall partially defining said recess 414 as shown in FIG. 8.

A transmission lever 431 is rigidly attached with a transmission lever407 for stopping the sixth wheel, andin such way that the both levers431 and 407 can perform a unitary swivelling movement around the pin405. One end of lever 431 is kept in resilient pressure contact with ashort arm 419e fonned on a stop lever 419 for stopping of the sixthwheel I representing a angular edged free end 4190 and is formed at itsintermediate point with a projection 419d having substantially atriangular configuration.

The lever 419 is formed with an elongated spring arm 41% the free end ofwhich is kept in resilient pressure contact with a stationary pin 401pstudded on the base plate 401, the lever 419 being urged resilientlythereby always to rotate in clockwise direction and normally positionedat the shown position in FIG. 8 by balance with the reversedly urgingspring force of the spring 409 which is transmitted to the lever throughthe short arm 419e.

It would be clear from the foregoing that under the action of spring 409the combined assembly comprising various transmission levers 406; 407and 431 is urged to rotate about pivot pin 405 in clockwise direction inFIG. 8, thereby the reset levers 41 1 and 413 and the stop lever 419being normally positioned at their respective off-service position asshown by solid line.

The operation of the fifth embodiment so far shown and described is asfollows:

In order to reset the seconds hand, minute and hour hands to zeroposition, the operator manipulates from outside the operating member404, thereby the transmission levers being urged to rotate in counterclockwise direction against the action of spring 409 and the tip end ofsaid extension 4060 of lever 406 within the inside space of recess 4112until it is brought into pressure contact with the opposite wall 411ddefining partially said recess. In this way, the lever 411 will rotatein clockwise direction about pin 41 1f, while the straight edge portion411a of lever 411 is brought into pressure contact with cam 417 which isbrought into rotation under the action of the lever 411 until the camisbrought to its a predetermined position for resetting the seconds handto zero.

At the same time, the elongated extension 407a of transmission lever 407will act upon the lever 413 so as to rotate the latter in clockwisedirection. In this way, the engageable end 412a of lever 413 is causedto invade into the vee-notch 416a formed on cam 416, providing that saidend 4120 is positioned within its resettable range relative tosaid'notch. In this way, the minute and hour hands, not shown, arerespectively reset to zero position and correct hour position.

On the contrary, when the cam 416 is so positioned that its vee-notch416a can not be brought into cooperating contact with straight edge part412a on lever 413, a manual push of operating member 404 will imitate areset of the seconds hand to its zero position in the aforementionedmanner, but the lever 413 is brought into contact with plain peripheralsurface of cam 416 other than the vee-notch 416a, whereby the elongatedextension 407a is slightly deflexed resiliently. Thus, a reset operationof the minute and hour hands can not be, therefore, brought about.

By the push-in manipulation of operating member 404, transmission lever431 is caused to act upon lever 419 which is thus rotated and thestraight edged lever end 4190 is brought into pressure contact withsixth wheel 421. In this way, this wheel 421 is caused to stop. Itshould be noted that on a certain intermediate shoulder 429a formed onminute hand arbor 429 (FIG. a seat ring 427 is mounted on this shoulderand the inner peripheral part of a perforated disc spring 428 is kept inpressure contact with the ring 427, while the outer periphery of thespring 428 is kept in pressure contact with second wheel 425, as mostclearly be seen from FIG. 90. Cam 416 is fixedly mounted on minute handarbor 429. After all, second wheel 425 is resiliently urged by saidspring 428 against the cam 416, so the second wheel is therefore kept infrictional engagement with the shaft 429.

A friction engagement unit of the similar structure as above is alsoprovided for the fifth wheel 422 shown in FIGS. 9c and 9D, although notspecifically described.

The operation of the fifth embodiment of the invention is as follows:

From the foregoing, it will be clear that by the provision of frictionunit between seconds hand arbor and minute hand arbor, on the one hand,and between seconds hand arbor and escape mechanism, on the other, thetime-keeping hand reset operation can be performed without invitingexcess stress in the time keeping and escape mechanisms, includingbalance wheel 403; sensing and drive coil assembly 430 onlyschematically shown by a chain-dotted-line block; and an index wheel 420and the like conventional constituents. Therefore, a more easy andsmooth seconds hand resetting to zero and those concerning the minuteand hour hands can be brought about almost instantly and in an accurateand positive way.

' In FIGS. 9A and 9B which constitute in combination a single sectionalelevation of the reset mechanism, including, as above mentioned, secondshand reset cam; minute and hour hands reset cam; transmission leversadapted for actuation of these cams; sixth wheel stop lever;transmission lever cooperating therewith, for assisting betterunderstanding of the invention in combination with FIG. 8.

As seen in FIG. 8, an elliptical member 418a is fixedly attached to thebalance wheel arbor 418 and acts as a flange provided in turn with animpulse pin 418b. This elliptical flange 418a cooperates, during thehands-resetting operation, with the projection 419d on the longer arm419a of sixth wheel stop lever 419 as schematically demonstrated byimaginary line in FIG. 8. This structure prevents effectively such atrouble that the balance wheel has been stopped at its neutral positionand a next intended starting of the balance wheel can not be initiated.

In the electronic watch as shown and fitted with index wheel 420 inplace of conventional anchor and conventional escape mechanism andoperable in the reversed escapement principle where the drive force issupplied from the side of the escapement, and if theseconds hand resetlever is actuated sooner than the sixth wheel stop lever 419, rotationof fourth wheel 426 by the lever 411 will be transmitted to index wheel420 and the teeth on the latter may be brought into strong pressurecontact with the impulse pin, which would invite damages of thesecooperating parts. It is therefore, in such type of electronictimepiece, very much desirable to let the sixth wheel stop lever 419operate sooner than the seconds hand reset lever 411. On the other hand,when the lever 413 initiate its reset operation sooner than the lever411, rotation of cam 416 will bring unintentional rotation of theseconds hand. If such an operation should occur, the operator would feedunpleasant feeling.

When, therefore, it is desired to initiate the rotation of cam 416 forminute and hour hands in advance of the realization of a cooperatingengagement of second hands res'et lever 411 with its related cam 417, apositive slippage must be invited between cam 416 and second wheel 425.The aforementioned mechanism shown and described as the fifth embodimentof the invention will obviate the aforementioned defect. It should bementioned that in the present embodiment, the slip torque at the fifthwheel 422, as converted into that appearing at the second wheel, isselected to be larger than that appearing at the second wheel 425.

Finally, referring to FIGS. 10A, 10B and 10C, the sixth embodiment ofthe invention will be described in detail hereinbelow:

This embodiment is exemplified as an electronic watch as in the case offoregoing fifth embodiment.

In the present embodiment, battery 502; balance wheel 503; seconds handreset cam 506; minute and hour hands reset cam 507; time-keeping geartrain constituents and frictional engaging units are of substantiallysimilar design and arrangement as in the foregoing fifth embodiment.Therefore, the structure and operation of the reset mechanism proper aredescribed below. Y

A minute and hour hands reset transmission lever 512 is pivotablymounted on base plate 501 by means of pivot pin 511, said lever beingformed with a tip end 512a which is kept in engagement with a recess 510formed on a minute and hour hands reset lever 508 and at the free endthereof. The lever 508 is formed with a slot 508a in which a pluralityof pins 509 studded on base plate 501 may slide along. Therefore, thanksto this pin-and-groove guide means, the lever 508 is slidable in thedirection of slot 508a.

Lever 512 is provided with a pin 517 studded thereon and a transmissionlever 516 is pivotably mounted on this pin 517, said lever 516 having atip end 517a kept in engagement with a recess 514a formed on secondshand reset lever 514 of substantially L-shape at its bend thereof.

Base plate 501 mounts rigidly a pin 515 around which second hands resetlever 514 is pivotable. Arm 514a of said lever 514 has a straight-edged,free end extremity 514b adapted for cooperating with the seconds handreset cam.

A return spring 518 is fixedly mounted on base plate 501 by pins 515 and518?. This spring 518 has an extension 518a, the end extreme 518b ofwhich is kept in engagement with transmission lever 516 and in proximityto its pivot point 517, thereby urging the transmission levers 516 and512 to rotate clockwise about pin 51 1.

Transmission lever 516 is kept in contact with operating member 504formed into a push button. There is provided stop pin 520 on base plate501 kept normally in engagement with the lever 514. These arrangementsassure that the whole reset and correction mechanism so far shown anddescribed is kept normally in the off-service position shown in FIG.10A.

When push button 504 is pushed in, transmission leversS 16 and 512 arecaused to rotate in counter clockwise direction around pin 511 whilekeeping substantially the relative position of the related parts in theposition shown in FIG. 10A. In this way, lever 516 acts by its end 517aupon lever 514 to rotate the latter in clockwise direction, thereby itstip end 514b being brought into pressure contact with cam 506 which isthus rotated for performing the corrective movement for the secondshand. I

At the same time, transmission lever 512 is caused to rotate counterclockwise, whereby the minute and hour hands reset lever 508 is shiftedin the axial direction of slot 508a and the free end of said lever beingbrought into engagement of cam 507 at its recessed part. In this way, acorrection of the position of minute and hour hands is brought about asbefore.

When the cam 507 for correction of minute and hour hands positionoccupies such position as being offset from registration with vee-recesson the cooperable cam 507, a finger pressure imposed upon the pushbutton will bring the end of the correction lever 508 into pressurecontact with the plain periphery of the cam 507 other than thevee-recessand thus, the correction lever 508 will move no more and onlythe transmission lever 516 will be caused. to rotate in a counterclockwise direction around the pin 517 against the return spring 518.Therefore, the operation of the second hands reset lever can not bedisturbed.

The embodiments of the invention in which an exclusive property orprivilege is claimed are as follows:

1. In a center second type timepiece wherein a seconds hand, a minutehand and a hour hand are arranged at the center of the timepiece andpower is supplied from the escape side of time-keeping gear traintowards said hands, characterized by a hands position correctingmechanism comprising a first cam means and a first correction levermeans related therewith and destined for correcting the seconds handposition and a second cam means and a second correction lever meansrelated therewith and adapted for correcting the minute and hour handsposition, an operating member accessible from outside thereto andadapted for actuation of said two lever means.

2. A hands position correcting mechanism as claimed in claim 1,wherein'said second cam means is adapted for performing a relatedcorrection job in a rather smaller range than that attributed for saidfirst cam means.

3. A hands position correcting mechanism as claimed in claim 1, whereinsaid correction mechanism is so designed and arranged that the secondshand is exclusively corrected in its position when a correction forminute and hour hands are not brought about.

4. A mechanism as claimed in claim 1, wherein said first cam means is inthe form of a heart cam attached to seconds hand arbor.

5. A mechanism as claimed in claim 1, wherein said second cam means ismounted on minute hand arbor or a certain arbor operatively connectedtherewith.

1. In a center second type timepiece wherein a seconds hand, a minutehand and a hour hand are arranged at the center of the timepiece andpower is supplied from the escape side of timekeeping gear train towardssaid hands, characterized by a hands position correcting mechanismcomprising a first cam means and a first correction lever means relatedtherewith and destined for correcting the seconds hand position and asecond cam means and a second correction lever means related therewithand adapted for correcting the minute and hour hands position, anoperating member accessible from outside thereto and adapted foractuation of said two lever means.
 2. A hands position correctingmechanism as claimed in claim 1, wherein said second cam means isadapted for performing a related correction job in a rather smallerrange than that attributed for said first cam means.
 3. A hands positioncorrecting mechanism as claimed in claim 1, wherein said correctionmechanism is so designed and arranged that the seconds hand isexclusively corrected in its position when a correction for minute andhour hands are not brought about.
 4. A mechanism as claimed in claim 1,wherein said first cam means is in the form of a heart cam attached toseconds hand arbor.
 5. A mechanism as claimed in claim 1, wherein saidSecond cam means is mounted on minute hand arbor or a certain arboroperatively connected therewith.